Here is my review about MX Player . MX player is application which can be installed on any android smartphone from playstore . Its used as an video player as well as an audio player . I had been using it from a long time and it was running smoothly till it started lagging in .mkv format videos . I thought it was the problem with only with my device but I found it on other devices as well . I bought the pro version , MX PLAYER PRO . I thought the problem would be fixed but the pro version was no different from the previous one . MX Player can run almost any type of video format but it lags too much that sound plays a few seconds before the video is displayed . Even though when listening to songs , It automatically stops , I checked the sleep timer in settings but I found sleep timer on 0. There are better options than MX Player . I would recommend usind VLC for Android instead of this laggy player